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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Does ocean cooling prove global warming has ended?

What the science says...

Early estimates of ocean heat from the Argo showed a cooling bias due to pressure sensor issues. Recent estimates of ocean heat that take this bias into account show continued warming of the upper ocean. This is confirmed by independent estimates of ocean heat as well as more comprehensive measurements of ocean heat down to 2000 metres deep.

Climate Myth...

Oceans are cooling
“Ocean heat touches on the very core of the AGW hypothesis: When all is said and done, if the climate system is not accumulating heat, the hypothesis is invalid.

[…]Now that heat accumulation has stopped (and perhaps even reversed), the tables have turned. The same criteria used to support their hypothesis, is now being used to falsify it.” (William DiPuccio)

As oceans contain around 80% of the climate's total energy, ocean heat is a good measure of what's happening with our climate. So recent ocean cooling has led some to conclude that global warming has stopped. Probably the most articulate article is The Global Warming Hypothesis and Ocean Heat by William DiPuccio. His logic is as follows:

Therefore, the anthropogenic global warming hypothesis is either false or fundamentally inadequate

Let's examine points 1 and 2 in more detail.

1. Does ocean heat monotically increase from year to year?

If the climate is steadily accumulating heat, does this mean the ocean heat content will also show a monotonic steady trend? To answer this, we need to view observations of ocean heat content over the past 40 years.

The longer record reveals short term variability amidst the long term warming trend. Volcanic eruptions (indicated in red by the stratospheric optical depth) impose a short term cooling influence of several years. But there is also variability due to cyclic effects such as El Nino. It's not unusual for the warming trend to slow or even show cooling over several years. More on what causes short term ocean cooling...

2. Has the ocean been cooling since 2003?

Ocean heat is directly measured by buoys that sink through the ocean, measuring water temperature at different depths. The most comprehensive system is the Argo network which was gradually deployed from 2003 through to 2007, with 3388 floats now spread throughout the globe.

There have been early difficulties in measuring ocean heat. Expendable bathythermographs, or XBT's, measured ocean temperatures before the Argo network was deployed. XBT's have been found to introduce a warming bias so when the warmer XBT data was combined with the later Argo data, the most recent trend showed exagerated cooling (more on that here). In addition, some Argo floats have had pressure sensor issues which impose a further cooling bias.

Loehles 2009 uses a reconstruction of Argo data by Josh Willis (Willis 2008). Another analysis of the same raw Argo data was performed by Leuliette 2009 - a comparison of Willis 2008 and Leuliette 2009 can be found in Figure 3:

Willis 2008 shows a cooling trend since 2004, while Leuliette shows a warming trend. The primary difference between the two is found early in the Argo record, when there were fewer Argo buoys deployed. Leuliette 2009 suggests the discrepancy between the two seems to be due to poor sampling and differences in how the data was handled. But which dataset is more accurate?

When confronted with two papers offering different results, a useful referree is an independently determined dataset. As well as using Argo data, Cazenave 2009 creates two independent estimates of ocean heat. Sea level rise is comprised of two components: mass change due to melting ice and steric sea level rise due to changes in ocean density. Thermal expansion is the main driver of steric changes (salinity is also a minor factor) so steric sea level rise is another measure of total ocean heat.

The first reconstruction uses satellite gravity measurements to calculate the change in ocean mass. They then subtract ocean mass sea level rise from total sea level rise to calculate the steric sea level rise. The second reconstruction uses satellite gravity measurements to calculate the change in mass of land ice and land water. The sea level rise from this contribution is subtracted from the total sea level rise to obtain another estimate of steric sea level rise. Both reconstructions show a statistically significant warming trend.

Argo offer two data streams - real time where the data is available almost instantaneously and delayed which undergoes more rigorous checks. Cazenave uses only measurements with the highest quality control settings (an approach the folk at Surfacestations would surely approve of). The Argo trend closely matches the other two reconstructions.

In climate discussions, the most common error is focusing on a single piece of the puzzle while ignoring the big picture. The ocean cooling meme commits this error twofold. Firstly, it scrutinises 6 years worth of data while ignoring the last 40 years of ocean warming. Secondly, it hangs its hat on one particular reconstruction that shows cooling, while other results and independent analyses indicate slight warming.

The bottom line is there is still uncertainty over the reconstruction of ocean heat. Generally, the various reconstructions show the same long term trends but don't always agree over short periods. The uncertainty means one cannot conclude with confidence that the ocean is cooling. Independent analysis seem to indicate that over last half dozen years, the ocean has shown less warming than the long term trend but nevertheless, a statistically significant warming trend.

Comments

"Dust Responsible for Most of Atlantic Warming", By LiveScience Staff, 26 March 2009

The results: More than two-thirds of this upward trend in recent decades can be attributed to changes in African dust storm and tropical volcano activity during that time. This was a surprisingly large amount, Evan said. The results, detailed in the March 27 issue of the journal Science, suggest that only about 30 percent of the observed Atlantic temperature increases are due to other factors, such as a warming climate. "This makes sense, because we don't really expect global warming to make the ocean [temperature] increase that fast," Evan said.

Lyman et al. 2006 and Gouretski and Koltermann 2007 both illustrate that the oceans have been cooling since 2003.

The same authors of Lyman et al. 2006 published a correction in 2007 noting that the apparent cooling had been an artifact of errors in the analytical method used. From their abstract:

"Two systematic biases have been discovered in the ocean temperature data used by Lyman et al. [2006]. These biases are both substantially larger than sampling errors estimated in Lyman et al. [2006], and appear to be the cause of the rapid cooling reported in that work."

Much has been published since then, including a followup by the same authors (Willis 2009)

"There was a concern that instrumental bias corrections might have affected the long-term trend (1955-2007) in ocean heat content that we previously reported. It will be demonstrated that, although some small corrections are indeed necessary, the instrument bias corrections do not affect the previously reported long-term trend in ocean heat content."

You have claimed there that "we've been in El Nino conditions for some time now and there's typically a short-term decrease in OHC when the cycle shifts from El Nino to La Nina". In #86 I have demonstrated beyond reasonable doubt, that recent decrease of OHC has nothing to do with ENSO. Just have a look at the figure.

I have also noticed there, that the 2003 jump in OHC may be an artifact due to instrumental change.

The NODC OHC graph shows an increase of about 5 × 1022 J in a single year. Since heat storage capacity of all other components of the climate system are negligible compared to the oceans, this energy could only come from an abrupt 3 W m-2 increase of radiative imbalance at TOA (Top of Atmosphere). Let us see.

Well, if ISCCP data are considered reliable, nothing like that has happened. There was a sharp decrease of some 4 W m-2 in net incoming flux at TOA between 2000 and 2002. Since then it is practically flat. Therefore reconstruction of OHC history before ARGO is suspect.

Sometimes you should use your own head. No amount of peer reviewed literature could save you that effort.

#87 Riccardo at 06:43 AM on 5 April, 2010 in same thread wrote:"you're dangerously falling into a grim denialism. You do not bother to verify you claims and let other people do the dirty job to make your denialism apparent. It's a bit boring"

Now. I kindly request our host to comment on this attitude. According to the site's Comments Policy"Comments using labels like 'alarmist' and 'denier' are usually skating on thin ice". A couple of other points come to mind as well. John, I would rather not ask you to delete that comment, as it also includes a false claim I'll comment on shortly, but it definitely deserves one of those green boxes.

#87 Riccardo at 06:43 AM on 5 April, 2010"Your claim about the jump in the deployment of Argo floats in 2003 which you immagine is the cause of the jump in OHC is blatantly false. Check youself (pag.4)."

Riccardo, you are referring to this image:

First things first. I have not claimed there was a jump in deployment. What I did claim, there is a jump in OHC reconstruction and at the same time instrumentation went through a huge change.

However, as you may notice, there is indeed a jump in Pacific ARGO deployments during 2003.

This jump is due to lack of ARGO floats in southern Pacific (to a lesser extent in southern Atlantic as well) during early 2003. The gap was filled in by December 2003, but it took another four months to get a reasonable distribution by random drift.

"Uses of Argo data
Perhaps the most important feature is that the array is now global and this permits us to start to address important scientific issues and to make the data useful to operational centres"

You can see how sparse OHC data really are prior to ARGO:

All other sources of OHC data also diminished dangerously by the year 2002. It is slide 6 in the Leviticus presentation:

Caption:The number of 4°x2° boxes that meet the observation criteria as a function of time for both MBT and XBT comparisons based on computations from WOD data.

Berényi Péter writes: Sometimes you should use your own head. No amount of peer reviewed literature could save you that effort.

It's important to use your own head and think about things for yourself. But when considering a highly complex subject outside your own area of expertise it's equally important (or more important) to make an effort to understand what people who spend their whole careers studying that subject have to say.

If one only uses one's own reasoning and disregards outside expertise, one is liable to be led into serious errors like this:

"[Water vapor] feedback is not positive. If it would be positive, the scenario described above [a runaway greenhouse effect like on Venus] is inevitable.

It is not climate science, not even physics. Just plain old math. Plus the empirical fact we are still alive."

If you will forgive me for making a critical comment, I think that this kind of disregard for learning from active scientists is one of the weaknesses of many of your comments here. I rarely if ever see you engage at all with the peer reviewed literature, which is a bit puzzling -- this site is unique among climate science blogs because of John's emphasis on discussing the peer reviewed literature, so if you have no interest in that, why do you comment here?

This current topic is a case in point. Many people have worked on reconstructions of ocean heat content from the 1950s or 1960s onward. There are debates within the field about the best ways to handle sparse data, the best ways to handle instrumentation biases, and whether there are sufficient data pre-1967 to permit a statistically valid reconstruction before that time. All of these are interesting topics and all of them are discussed in great detail in the literature.

Against all that, we have your flat assertion that pre-ARGO ocean heat content data are unreliable. Why? Well, you just say "look at this graph". It's not clear what you think you see in that graph. Oddly enough, the graph itself (here) is actually from a paper titled "Global ocean heat content (1955-2008) in light of recent instrumentation problems," a paper in which the authors describe how they were able to reconstruct ocean heat content from 1955-2008 in spite of various difficulties associated with pre-ARGO instrumentation.

Why would you link to that as justification for your claim that the pre-ARGO data aren't reliable?

I have no doubt that when you write something like "In #86 I have demonstrated beyond reasonable doubt, that recent decrease of OHC has nothing to do with ENSO. Just have a look at the figure" you sincerely believe you have in fact demonstrated that beyond a reasonable doubt. But alas, what seems convincing to you may be completely unconvincing to others. This is the advantage of testing your understanding against the accumulated expertise of scientists working in the field.

#6 Ned at 11:04 AM on 6 April, 2010"If one only uses one's own reasoning and disregards outside expertise, one is liable to be led into serious errors"

Yes. That's a risk one should accept. However, mistakes can (and should) be corrected. Let's discuss it under the proper topic, please.

On the other hand, the only way to actually understand anything is by trying to reproduce it on your own. There is no royal road. "Now there are many things that seem to be grounded in truth and to follow from scientific principles but actually are at variance with these principles and deceive the more superficial. It was for this reason that Euclid set forth methods for intelligent discrimination in such matters, too. With these methods not only shall we be able to train beginners in this study to detect fallacies, but we shall be able to escape deception ourselves".

You also ask:Why would you link to that as justification for your claim that the pre-ARGO data aren't reliable?"

I suppose you have read the paper. If so, you can see it has nothing to say about the 2003 step-like increase of OHC. Without it most of the multi-decadal trend is gone.

Energy conservation is a pretty solid principle. If it ever gets falsified, it would not happen in climate science.

Berényi Péter,
i apologize for my too strong wording. But since, contrary to you claim, it is evident from the very same graphs you show (e.g. your third graph) that nothing particular happened in 2003 it really makes me think that you did not go through the data thoroughly and just threw your hypothesis to negate the validity of the OCH data. I would not call this skepticism.

Berényi Péter writes: Without it most of the multi-decadal trend is gone.

I don't think so. Here's Levitus et al.2009 figure S9, showing a comparison of three different analyses of OHC from the 1950s onward. Since you think there is a problem in 2003 I've cropped the graph at 2002. The long-term multidecadal increase in OHC is obvious in all three studies.

Figure S9 from Levitus et al. 2009. Yearly time series of ocean heat content (10E+22 J) for the 0-700 m layer from this study and from Domingues et al. [2008] and Ishii and Kimoto [2008]. Linear trends for each series for 1969-2008 given in the upper left portion of the figure. Reference period is 1957-1990.

You still haven't given any evidence that pre-ARGO OHC data are "unreliable". Since that claim contradicts the results of multiple peer-reviewed studies showing long-term increases in OHC, one would demand very convincing evidence, but you provide no evidence at all, merely assertions.

I think we can conclude that the oceans have in fact been warming over the past half-century. This should be no surprise, since oceans cover more than half the planet, and the surface and atmosphere are also warming.

Berényi Péter pardon me for butting in but you're not the only person remarking on year 2003 as appearing as some sort of wild excursion.

However, if you look at the data you that 2003 simply marks the onset of three years of temperature upticks. Looking at the rest of the graph, I don't see anything unusual about these years other than we see three upswings in row.

In short, OHC in 2003 does not exhibit a "stepwise increase." 2003 itself is normal in terms of typical Y-axis behavior of this graph, as are other years subsequent to 2003.

The "Gambler's Fallacy" tells us we should not be surprised by such an outcome.

Wait a minute, perhaps Berényi Péter objects to the relatively large increase 2003-2004? But why should we arbitrarily decide a particular year's increase is an error simply because it's the largest difference on the graph? How would the record get stuck "up" after that year, if the year in question were indeed wrong? If anything, we ought to see an downward swing after such an error but we don't.

Berényi Péter, perhaps you should supply a hypothesis to explain how one year's error can influence subsequent derivations of OHC?

What strikes me about this figure is how close the agreement is among the three different teams. That's pretty remarkable.

The general upward trend, on the other hand, is less remarkable. Since there are multiple other lines of reasoning to suggest that OHC ought to have been increasing over the past half-century, it's not really surprising. But it's a nice confirmation of what one would expect.

#15 Ned at 05:04 AM on 7 April, 2010What strikes me about this figure is how close the agreement is among the three different teams

By the year 2004 the difference between Leviticus vs. Ishii & Kimoto is more than 6 × 1022 J. Of course you can call this agreement close, provided the meaning of this word is redefined.

In fact the discrepancy between them is so large, that huge error bars are needed to make them consistent. With those error bars I would be surprised to find a trend different from zero at any reasonable level of significance. It would be nice to have all the data in digital format and perform such a test.

Anyway. Even by eyeballing (and disregarding lack of significance) the trend between 1959-2001 is 0.2 × 1022 J/year perhaps. It translates to a 0.12 W/m2 net "forcing" at TOA on average during this 42 years long interval.

On the other hand according to the Mauna Loa record, CO2 has increased from 315.98 ppmv to 371.07 ppmv. If we accept the estimated sensitivity of 3.7 W/m2 for carbon dioxide doubling given in IPCC AR4 WGI 2.3.1 as a reference point, it should mean a 0.86 W/m2 increase in "forcing" by the year 2001 relative to 1959.

Log CO2 being almost linear, average should have been 0.43 W/m2. More than 70% of it is nowhere to be found. And not even feedbacks are taken into account yet. With them the effect measured is barely more than 10% of the radiative imbalance projected by IPCC.

The artificial jump of 2003 introduced by Levicus at al. would not improve the situation much. It would make the figure above 15-20% perhaps (of expectations based on mainstream climate science).

Either OHC history reconstructions are useless or theory misses some strong negative feedback.

Berényi Péter, you do need to supply a hypothesis better than simply being suspicious of what could be a coincidental string of increases in observed OHC over 3 years. That's not really a workable hypothesis at all, not without elaboration.

Assuming your notion about instrumentation changes is valid, I think you're missing a potential explanation for the "anomalous jump" you see, namely that adding instrumentation improved our ability to measure OHC. If I buy into the idea that 3 years of increasing OHC is down to instrumentation issues, I can as easily say the increase is due to better perception as you may say it's an error introduced by instrumentation changes.

Without doing more work, neither of us can be believed. The problem is, neither of us really knows what we're talking about here, not with the degree of expertise needed to sort out the instrumentation problem you believe you see. Fortunately, we amateurs are not the last word on this matter, instead we've got actual scientists working on the case. After all of our handwaving is finished, they're still the horse's mouth with regard to this issue.

BP writes: Anyway. Even by eyeballing (and disregarding lack of significance) the trend between 1959-2001 is 0.2 × 1022 J/year perhaps. It translates to a 0.12 W/m2 net "forcing" at TOA on average during this 42 years long interval.

This seems a bit low. I get 0.26 W/m2 at the ocean surface, not 0.12 TOA, and TOA should be *higher* because of the albedo.

For comparison, NASA GISS has a table of annual net radiative forcings here. If you take the 1969-2003 forcings, multiply them by the area of the ocean and convert to J/year, the average over that time period is 1.0E22 J/year.

So the OHC700 trend from those three papers is anywhere from 24% to 41% of what GISS suggests it should be. That's a bit low, even assuming some of the heat is going into the ocean below 700m.

I'm going to have to read and think more about this; I may be forgetting something.

For comparison, Domingues shows the following figure comparing their results to model predictions, including those of GISS:

That seems to show their observations falling nicely in the middle of the ensemble of models, which is hard to reconcile with a trend that's only 24% to 41% of what would be predicted from forcings. Unfortunately at the moment Nature's website seems to be down so I'll have to go back and reread Domingues later to see how they explain this.

All that said, I think Doug Bostrom has the most important point here: Without doing more work, neither of us can be believed. The problem is, neither of us really knows what we're talking about here, not with the degree of expertise needed to sort out the instrumentation problem you believe you see. Fortunately, we amateurs are not the last word on this matter, instead we've got actual scientists working on the case.

We do not know the correct offset, so the zero level is arbitrary, but there was no any climatically relevant change detected in this period. There might have been instrumental problems in 2000-2001, none later.

That is, from 2002 to 2003 OHC increased by 3.386± 0.751 × 1022 J and it has decreased by 0.907 ± 0.665 × 1022 J between 2004 and 2005. The difference is 4.293 ± 1 × 1022 J.

It means that Earth has accumulated that much more heat in 2002-2003 than in 2004-2005. As Earth surface area is 5.1 × 1014 m2, the difference in net radiation balance is 8.42 ± 1.96 × 107 J/m2. A year is 3.16 × 107 sec. Therefore the difference in net radiation flux should have been 2.66 ± 0.62 W/m2.

That is, from 2002-2003 to 2004-2005 Total Net Global Mean Anomaly at TOA should have decreased by at least 2 W/m2. It would be very visible in the ISCCP-FD graph, but in fact nothing like that can be seen.

The extra heat needed to increase OHC in 2002-2003 could come from nowhere else than from TOA radiation anomaly, since there is no component in the climate system other than the oceans capable to store and supply that much energy. But it could not come from above. Therefore the NODC reconstruction is flawed. Q.E.D.

BTW, even the Levitus OHC history reconstruction gives only a 0.14 °C increase in temperature for the upper 700 m of oceans for the entire 53 year period between 1955 and 2008.

It is a problem indeed. Same author says average thermosteric sea level rise for this period was 0.39 mm/year.

For a 700 m deep water column to expand by 20.7 mm in response to 0.14 °C warming, volumetric thermal expansion coefficient should be 2.1 × 10-4. It can only happen if average temperature of the upper 700 m is more than 20 °C.

Now. In fact average temperature of ocean surface waters is 17 °C and this is the warmest layer. Below the thermocline (100-200 m on average) it gets really cold fast. At 700 m it can not be more than 5-6 °C. Therefore average temperature for the upper 700 m is somewhere around 10 °C. At this temperature volumetric expansion coefficient of water is only 0.88 × 10-4.

It means that either OHC increased twice as much as Levitus claims or steric sea level rise was half of his value. There is of course a third, most unlikely possibility: temperature of seawater might have increased only in the warmest parts and layers of the ocean and nowhere else.

The Argo network is quite new, expanding rapidly over the last few years, and proper calibration methods are apparently still being developed.

The current Argo data (not the badly calibrated 2006 data), along with currently calibrated XBT data from the past, is shown and linked to here.

While the last few years (Argo only data) are not increasing at a high rate, they are showing some increase in ocean heat content over that period. Given the inherent variability of the measurements, I don't think that any "decline" can be statistically justified using just the last 7 years of data. Incidentally, you stated that you weren't making any claims about trends? Isn't stating that OHC content "...has got definitely smaller in seven years" a trend statement?

I think it's only reasonable to use statistical analysis on a noisy sample - making claims without statistics is, well, not convincing.

In (I believe) the Why are there fewer weather stations thread someone noted that the temperature anomalies (not temperatures, but anomalies) seen across the surface record have a high correlation over fairly large areas, and hence a reasonable surface temperature anomaly record could be obtained with just a few hundred stations.

Is this the case with the Argo and XBT data? Do OHC measures display large area correlations in anomalies, or does the 3D current structure of the ocean prevent that?

I'm wondering just how many Argo floats (or better yet, some deeper samples) are required to accurately measure ocean temperatures.

BP, I will also reply in the correct thread with a quantified followup to your claim: "Heat content anomaly of the upper 700 m of oceans in the fourth quarter of 2003 is 11.655±0.975×1022 J, while in the third quarter of 2010 it is 9.589±0.690×1022 J,....a net heat loss (of at least 4×1021 J)."

The Loehle paper http://www.ncasi.org/publications/Detail.aspx?id=3152 shows about a 5×1022 J annual cycle of OHC. From the third to fourth quarter every year the rise is about 2×1022 J or a loss of 2×1022 J when picking a fourth quarter as a starting point and a third quarter as an ending point. or about 5 times the loss you stated in the other thread. The reason is simply that the earth gets closer to the sun during that interval each year.

But then again it seems that you think that you know more about OHC than Palmer, Lyman, Trenberth, Levitus, Domingues, von Schuckmann, Good,Gouretski, Ishii, Komoto, Johnson, Smith, Haines, Murphy, Reseghetti, Antonov, Mishonov, Garcia, Locarnini, Boyer and Willis.

You are railing against an awful lot of grey matter, experience, expertise and training BP. Something else to consider, according to Palmer et al. (2009):

"Deep ocean warming may account for some of the missing energy (Johnson and Doney 2006; Johnson et al. 2007; Johnson et al. 2008a). Only with a truly global ocean observing system can we close fully the global energy and sea level budgets, so we must improve our observations of the ocean below 2000 m where Argo floats currently do not reach."

Well indeed why don't we invite Palmer, Lyman, Trenberth, Levitus, Domingues, von Schuckmann, Good,Gouretski, Ishii, Komoto, Johnson, Smith, Haines, Murphy, Reseghetti, Antonov, Mishonov, Garcia, Locarnini, Boyer and Willis to comment on BP's analysis. Surely John Cook has some contacts with some of these scientists who could be asked to comment.

The nub of BP's argument is simple:

Satellite measurements of absolute TOA imbalance is poor to useless (not even the sign is sure), but month on month and year on year precision is good (ie the deltas).

The jumps in the OHC charts published 1993-2009 (Trenberth 2010 above) and Lyman composite show OHC gains 2001-03 of about 7E22 Joules (700E20 Joules) which is a rate of about 350E20 Joules/yr.

Trenberth's 0.9W/sq.m TOA imbalance equates to 145E20 Joules/yr. To get a 350E20 Joules/yr increase in OHC, the TOA imbalance must have leapt from 0.9 to 2.2W/sq.m in the period 2001-03.

Satellite measurement shows no such change in that period.

The period coincides with the XBT to Argo transition, so which is right? - high precision delta measurement by established satellites or XBT-Argo in transition??

I would plug for the Satellites.

The conclusion is that the step jumps in OHC Charts in this period are an artifact of the transition, and the greater deployment of Argo shows flat OHC since ARO 2003.

Therefore, drawing a linear curve fit (the red line on Trenberth 2010) from 1993-2009 and calling it a 0.64W/sq.m (or 103E20 Joules/yr) rate of TOA warming imbalance is bogus if the step jump is incorrect.

The blue line (o.54W/sq.m) looks like a dodgy fit as well as it should terminate somewhere near the end of the red line I would have thought.

Arguing that BP's 7-8 year period is ridicuously short, is ridiculous itself in the context of OHC Charts which only span 16-17 years (1993-2009).

#33: "No warming imbalance for 7-8 years is a terminal inconsistency in the whole theory of AGW"

Looking at the graph in #34, I would have to agree; The current 7 year flat spot, if real, is terminal. Just like the flat spot from 1982-1988 was terminal. Guess AGW stopped then, too. Or like it stopped in the late '60s on the graph in #25.

Or maybe OHC does have an upward trend, with some more complex behavior that gives rise to these occasional residuals. Funny how one can argue that there's no warming based on a shoulder in the upward trend, all the while ignoring the upward trend itself.

On the other hand I have used the OHC reconstruction published online at the NOAA (National Oceanic and Atmospheric Administration) NODC (National Oceanographic Data Center) OCL (Ocean Climate Laboratory) site, based on Levitus 2009 and updated regularly.

Fortunately the NOAA NODC OCL OHC site also has annual data in tabular format with proper error bars. If it is copied to your figure, it looks like this:

Now. As you know science is never about pictures. It is about propositions, preferably with a truth-value attached to them or at least a not-known tag. Figures like the one above is only meant to be concise representations of complex propositions.

For example OHC history reconstruction according to Levitus can be translated to a proposition like "There is a constant c that if ohck is the sum of c and the true value of OHC measured in 1022 J units for year k, then 0.246 < ohc1993 < 1.122 and 0.764 < ohc1994 < 2.256 and 1.615 < ohc1995 < 2.913, etc., etc."

A similar proposition can be constructed for the curve in your figure which is Trenberth's representation of Lyman's finding.

If you put the two propositions together like I did above by making a joint representation, it is clear that they contradict each other. Therefore if they are supposed to be joined by the logical operation conjunction as the graphical representation suggests, what you get is a false proposition. As you know, from a false proposition anything follows with the force of logical necessity, and of course among the many possible consequences there is the one you are seeking. Or its negation.

The problem is the error bars do not overlap. If it happens for different measurements of the same quantity, it is a sure sign it was not a measurement just some pure guesswork. Based on guesswork (as opposed to measurement with proper error analysis) you can never say things like "OHC is increasing". Of course you can say "I guess OHC is increasing" or "the educated guess (using some as yet unspecified system of fuzzy logic) of Palmer, Lyman, Trenberth, Levitus, Domingues, von Schuckmann, Good, Gouretski, Ishii, Komoto, Johnson, Smith, Haines, Murphy, Reseghetti, Antonov, Mishonov, Garcia, Locarnini, Boyer and Willis is that OHC is increasing",. However, it is not a factual statement, but a proposition regarding the personal or community beliefs of a group of individuals. As such, it belongs to the field of social, not natural sciences.

Berényi - I have seen a consistent slant in your postings. In all cases, if there is any uncertainty whatsoever, you put forth the propositions that global warming isn't happening/is less than expected/that negative feedbacks will save us.

Now, I will be one of the first to say that OHC measurements are not the best data we have. And that satellite TOA measurements are precise, but not as accurate as we would like.

But - Consistency is not just the hobgoblin of little minds. The majority of the indicators (ice melt, surface temps, flora region migration, physics of CO2, etc.) point in a singular direction. OHC measures are clearly imprecise, poorly calibrated, and only measure the top 700 meters of rather deep oceans. Are they the Michelson–Morley experiment of global warming, as you propose, or are they simply a rather imprecise measurement???

This is experimental science, not a logical exercise in a toy mathematical domain, Berényi. The mass of evidence indicates continuing global warming. Occams's razor would indicate that the error(s) are in the OHC measurements and are limits thereof, rather than in everything else we know.

Please - consider the fact that this is experimental science, not a logical proposition with fixed premises, and look at the weight of evidence.

"No one is claiming that. The fact that there are large seasonal temperature variations in no way contradicts a long equilibrium time. With seasons we are not talking about equilibrium time because, as Tom says, the hemispheres do not reach equilibrium with the max and min values of insolation and albedo. No where even close."

OK, let's run some numbers. The northern hemisphere surface air temperature increase at peak summer is over 10 C on average. The sea surface temperature increase is about 5 C. This is an enormous accumulation of heat in a very short period of time - only 6 months, during which only part of the +100 W/m^2 peak solar energy is forcing the hemisphere. Let's say hypothetically speaking, the earth were to suddenly remain at its maximum summer tilt angle permanently. If the equilibrium response time were a decade, then we should expect at least an accumulation of over 20 C a year air and about 10 C ocean, correct? Over ten years, that amounts to over 200 C air and 100 C ocean.

That is obviously way too high, don't you think?

Let's shorten the time span to only 2 years. That would still amount to over 40 C air and 20 C ocean.

"On a hypothetical Earth where we instantly doubled the CO2 from 280ppm to 560ppm, the bulk of the temperature change would indeed be felt within the first few years, but full equilibrium is not reached for a century or longer according to climate commitment studies (try Meehl 2005"

This is interesting. I though the AGW theory is saying the opposite of this - that is most of the warming is in the pipeline and yet to occur?

RW1, please look at the paper I linked in #31 which gives an estimate of the seasonal ocean heat storage (5×1022 J trough to peak). Then compare that to the seasonal increase in TSI (need to integrate the increased power over the same portion of the year). Unfortunately I do not have the numbers to do that. Then compare the two and see how much of the extra solar energy made it into the ocean in one season.

"If the equilibrium response time were a decade, then we should expect at least an accumulation of over 20 C a year air and about 10 C ocean, correct? Over ten years, that amounts to over 200 C air and 100 C ocean."

Ah, I wondered if this was your issue. Nonlinear, RW1, Nonlinear. As the Earth warms, the more it emits (a la Stefan-Boltzmann), the less the imbalance becomes = less energy builds up in the system per unit time. Temperature will follow a roughly logarithmic curve with a horizontal asymptote at the new equilibrium temperature.

"This is interesting. I though the AGW theory is saying the opposite of this - that is most of the warming is in the pipeline and yet to occur?"

No - ~0.8C seen so far, ~0.6 to go. But this issue is complicated by other forcings and a gradual (but increasing) buildup of CO2. That's why I gave the hypothetical Earth example to simplify things.

"Ah, I wondered if this was your issue. Nonlinear, RW1, Nonlinear. As the Earth warms, the more it emits (a la Stefan-Boltzmann), the less the imbalance becomes = less energy builds up in the system per unit time. Temperature will follow a roughly logarithmic curve with a horizontal asymptote at the new equilibrium temperature."

Some of the nonlinearity was factored in because it's not +100 W/m^2 for the whole 6 months. OK, how should we calculate the non linear response given these knowns (+10C surface air and about 5 C ocean)? Let's run the numbers - it still isn't going to be anywhere near a decade.

RW1 - You are still not looking at this from a standpoint of penetration depth. Given the thermal conductivity and circulation patterns of the oceans, it takes time for heat to reach the deep ocean, and hence short term seasonal variations do not penetrate very far into the ocean mass. The total mass changing temperatures up and down is a relatively small portion of the ocean thermal mass.

A constant offset, on the other hand (like the current energy imbalance) held over what is now multiple decades - that has time to affect deep waters, and affect the average temperatures.

If I take a brick and repeatedly pass a hot torch and a block of ice over the top of it, the bottom of the brick will change temperature almost not at all. If, on the other hand, I sit an electric blanket on it all day, the bottom of the brick will warm up. Penetration depth, and time for heat transfer!

RW1 - "Neither will the top of the brick." Really? The top of the brick will alternately be hot enough to burn your hand and cold enough for a nice iced drink.

As to why a brick - I thought that a simpler case for discussing slow thermal transfer from top to bottom.

Only the upper layer of the ocean gets seriously involved in short term seasonal temperture/insolation variations, and since it's a fairly small mass it changes quite a lot. But a constant offset? That has time to sink in, to change the deep ocean. And hence the average temperature of the oceans.

You can prove that there is heating in the pipeline, as it were, by using a simple capacitance relationship: I = C * dV/dt, where C is the heat capacity of a block of ocean, dV is the change in temperature, I is the amount of power injected into the block of ocean, and dt is the time it takes to heat up the amount dV. Note that I used electrical terminology because of my EE background, but the math is the same.

Rearrange the terms to solve for dt and then do a little digging for the heat capacity of a block of seawater, and ta-da, you've got your first-order approximation of the answer. It neglects seasonal variations, convection, and radiation, and heat conductivity so it's hardly perfect, but it's a good starting point. Add heat conductivity and the time goes up. Add convection and radiation and the time drops. Add seasonal variation and the time shouldn't change much if at all.

"The top of the brick will alternately be hot enough to burn your hand and cold enough for a nice iced drink."

I wouldn't think so - I think the whole brick would warm and cool, but a pot of water would be more analogous to use. That's not going to work either though, I don't think.

"Only the upper layer of the ocean gets seriously involved in short term seasonal temperture/insolation variations, and since it's a fairly small mass it changes quite a lot. But a constant offset? That has time to sink in, to change the deep ocean. And hence the average temperature of the oceans."

Why? What is the physical reason? If the whole ocean participated in the thermal mass, the short term seasonal warming could not occur. There is no reason to believe the tiny little increase from CO2 wouldn't also change the ocean surface temperature just a quickly. The question is equilibrium time per incremental amount of forcing - not whether or not gradual changes in the upper ocean layers can eventually trickle to the deep ocean waters somewhat. There are also many reasons why the temps of deep ocean waters can change.

That is a standard high school physics demonstration. I promise you the back side of the brick stays much cooler than the rapidly heated side.

"What is the physical reason? If the whole ocean participated in the thermal mass, the short term seasonal warming could not occur."

Let's lose the hypothetical nature of this question and start with the observation that seasonal warming and cooling does indeed occur. We certainly can agree that ocean surface layers therefore act as if they have low thermal inertia and participate in these relative rapid changes.

As to the greater inertia question, do you agree with the analysis presented by NOAA here?

The seasonal variations in heating penetrate into the ocean through a combination of radiation, convective overturning (in which cooled surface waters sink while warmer more buoyant waters below rise) and mechanical stirring by winds.There are your mechanisms.

... These processes mix heat through the mixed layer, which, on average, involves about the upper 90 m of ocean. The thermal inertia of a 90 m layer can add a delay of about 6 years to the temperature response to an instantaneous change ... As a result, actual changes in climate tend to be gradual.There is the reason why 'the tiny little increase from CO2' does not change the ocean temperature quickly.

With its mean depth of about 3800 m, the total ocean would add a delay of 230 years to the response if rapidly mixed. However, mixing is not a rapid process for most of the ocean ... An overall estimate of the delay in surface temperature response caused by the oceans is 10–100 years. --emphasis added

All of that inertia, without any discussion of the complicating roles of density layering and thermocline structure.

Salinity effects on ocean density are also important but are poorly measured at present. It is essential to be able to attribute changes in ocean heat content and the mass of the ocean to causes (such as changing atmospheric composition), perhaps using models. Climate models suggest that the THC could slow down as global warming progresses, resulting in counter-intuitive relative regional cooling or, more likely, reduced warming on multi-decadal time-scales.